Conventional railroad vehicles, particularly high-speed railroad vehicles include ones equipped with a plug door. The plug door has a door form such that the outer surface thereof is flush with the outer surface of a vehicle body when the doorway is closed. This plug door allows reductions in air resistance and noise such as wind noise.
As for such plug door, Patent Literature 1 listed below discloses a plug door device for a vehicle, in which a slide rail 10 extending toward a side wall of a vehicle body is coupled to a guide rail 6 extending in a longitudinal direction of the vehicle body, so as to allow movement along the guide rail 6, and a door 3 is coupled to the slide rail 10 so as to allow movement along the slide rail 10.